#define _CRT_SECURE_NO_WARNINGS 1

#include<stdio.h>
int main()
{
    int n = 0;
    int h = 0;
    int m = 0;
    scanf("%d%d%d", &n, &h, &m);
    int left = 0;
    if (m % h != 0)
        left = n - m / h - 1;
    else
        left = n - m / h;
    printf("%d\n", left);

    return 0;
}